1. Field of the Invention
The present invention relates to an opening and closing type interior device which is disposed, for example, in an automobile, and more particularly relates to an opening and closing type interior device which can suppress generation of noise.
2. Description of Related Art
A typical conventional opening and closing interior device includes a display device for an automobile. The display device includes a fixed member, a movable member rotated about a rotational axis relative to the fixed member so as to be opened and closed, and an actuator for driving the movable member to rotate so as to be opened and closed. The actuator includes a driving source, and at least one gear (generally, a plurality of gears) disposed in a driving force transmission path.
A backlash is provided in each engaging portion of gears. The backlash absorbs dimensional deviations between the gears, thermal expansion in the gears and the like, thereby securing an appropriate engagement between the gears.
However, there is the following problem with the conventional device.
When the movable member is opened and closed, a center of gravity of a movable assembly, which includes the movable member and a member or members rotatable together with the movable member, crosses above the rotational axis of the movable member and produces a moment. The moment caused about the rotational axis is due to the weight of the movable assembly and changes as the center of gravity of the movable assembly crosses above the rotational axis, so that the load imposed on the actuator for opening and closing the movable member reverses between a positive load and a negative load. As a result, the engagement of a driving side gear of the actuator with a driven side gear of the actuator is reversed, causing hammering in the gears due to the backlash of the gears thereby generating noise.